Cold hardiness & minimum temperature

Is Laza Cyphostemma (Cyphostemma laza)cold hardy? Hardiness zone & min temp

Also called Laza Cyphostemma, Laza Grape, Laza Tree.

More about laza cyphostemma

About Laza Cyphostemma

Cyphostemma laza · also called Laza Cyphostemma, Laza Grape · tropical

A spectacular caudiciform vine endemic to the arid rocky hills of Madagascar, prized for its massive swollen caudex that can exceed 500 mm across and vining stems that extend several metres. Bright, direct sun and generous summer water with a completely dry winter rest are essential. A slow-growing collector's plant of great ornamental drama.

Cold limit: USDA 10b–11 · RHS H1b (13–35°C)

Watch for — Overwatering / caudex rot: The swollen base is vulnerable to rot if kept wet during dormancy. Ensure near-complete dryness throughout winter and use an extremely free-draining substrate.

What laza cyphostemma's hardiness rating actually means

Laza Cyphostemma is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Its RHS rating of H1b means: Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season. On the US scale that maps to USDA 10b–11 — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly about 10 °C (sustained cold below this is damaging). Laza Cyphostemma has no frost tolerance at all — it is an indoor plant in any climate with a real winter.

Concretely, for laza cyphostemma as it gets too cold:

Below about about 10 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches.
A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover.
Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.

Can laza cyphostemma go outside or overwinter — and where?

It can holiday outdoors in summer once nights are reliably above 10 °C, in shade or dappled light, hardened off gradually.
Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C.
It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when laza cyphostemma can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H1b figure above.

Laza Cyphostemma hardiness — frequently asked questions

Is laza cyphostemma cold hardy?

Laza Cyphostemma is not cold hardy. It is a tropical houseplant that dies if it is left out through frost — there is no zone where it overwinters outdoors in a UK or cold-US climate. Indoor-only in almost every home. Laza Cyphostemma can only live outside year-round in genuinely frost-free climates (roughly USDA 10b–11); everywhere else it is a houseplant that summers out at most.

What is the minimum temperature laza cyphostemma can survive?

What hardiness zone is laza cyphostemma?

Laza Cyphostemma is rated USDA 10b–11 and RHS H1b — Sub-tropical — a normal warm home is fine, but it cannot go outside in a cool season.

Can laza cyphostemma survive winter outside?

It can holiday outdoors in summer once nights are reliably above 10 °C, in shade or dappled light, hardened off gradually. Bring it back indoors well before the first autumn frost — do not wait for a frost warning, move it when nights drop toward 10-12 °C. It will never overwinter outside in a temperate climate; the indoors is its winter home, full stop.

What happens to laza cyphostemma below its minimum temperature?

Below about about 10 °C, growth stalls and the leaves start to show cold stress — dark, water-soaked, or yellowing patches. A single light frost blackens the foliage; a hard freeze kills the whole plant, roots included, and it does not recover. Even a cold, draughty windowsill or an unheated porch in winter can be enough to damage it permanently.